The present invention relates to an auxiliary oil filter system for automobile engines.
The primary oil filter of most automobile engines, commonly referred to as a spin-on filter, filters the entire normal oil flow and is commonly situated between the oil pump and the engine's moving parts. It is normally mounted on the engine crankcase. This filter must be relatively porous in order to maintain a certain degree of oil pressure throughout the engine. Most models are provided with a safety valve which opens when the filter becomes clogged in order to keep the oil (all be it unfiltered) flowing through the engine. A finer porosity auxiliary or secondary oil filter system is sometimes provided to divert a portion of the normal oil flow and filter that portion beyond the level of filtration achieved by the primary oil filter. Such systems normally comprise an auxiliary oil filter mounted on a bracket external to the engine crankcase and connected to the crankcase via a flexible hose. The connection involves drilling a hole through the crankcase, thus increasing the risk of oil leakage.
Auxiliary oil filters are commonly of the canister type with replaceable filter elements. The filter elements are often of the toilet paper roll type and are messy and inconvenient to replace. It is also difficult to tell when the filter elements of such filters need replacing, a condition which tends to diminish the efficiency of such devices since they can become unsuspectedly clogged and remain so until the next maintenance service.